Set up labels to denote the BSS and init/exit table segments

Again, we can't split dseg into the "real" segments just yet, because that
would force us to correct the assumed data segment in every single function.

[Binary change] Relocations in TH01's FUUIN.EXE. Again.
[Reduction] #50: setenvp
[Reduction] #51: Standard FILE structures

[Binary change] Relocations in TH01's FUUIN.EXE. (...)